can formamide harbour RNases?

Dear netters,
I was wondering if formamide can harbour any RNases. We were de-ionizing
our formamide using Sigma's Amberlite Mesh16-50. We used the newly
de-ionized material for our RNA denaturing buffer and everything
including the ladder was degraded. I used a 2 month old denaturing buffer
that included ( Formamide, formaldehyde, MOPS, Depc H2O) and it worked
(so much for needing to make this stuff FRESH).
Thanks for your input.
Cheers
--
Shahram Mori _/\_
Program in Molecular Biology _\ /_
Dept. of chemistry and Biochemistry Box 3C \_ _/
NMSU Las Cruces NM ||
88003